柴油机SCR催化器NO_(x)转化效率影响因素的数值分析  

Numerical Analysis of NO_(x) Conversion Efficiency of SCR Catalytic Converter of Diesel Engine

作　　者：赵浩 何伟[1] ZHAO Hao;HE Wei(Faculty of Mechanical and Electrical Engineering,Kunming University of Science and Technology,Kunming 650500,China)

机构地区：[1]昆明理工大学机电工程学院,云南昆明650500

出　　处：《电子科技》2022年第6期89-94,共6页Electronic Science and Technology

基　　金：国家自然科学基金(51168020);云南省应用基础研究计划(2013FZ024);昆明理工大学测试基金(2019M20182103041)。

摘　　要：为探究旋流混合器温度以及尿素注入流量对NO_(x)转化效率的影响,以某柴油发动机SCR催化器为研究对象,运用CFD技术对其进行化学反应和稳态流动数值模拟。通过改变旋流混合器的温度和尿素注入流量,对比分析不同情况下NH3的浓度与均匀性系数以及出口处NO_(x)的质量分数。研究结果表明,SCR催化器出口处NO_(x)质量分数分布呈现中心低边缘高的规律,旋流混合器温度的变化对NH3速度均匀性系数影响较小。在其温度为400℃时NH3分布较均匀,NH3生成率和NO_(x)转化效率较高。结果表明,选择合适的尿素注入流量,能够提高NO_(x)转化效率和尿素利用率。In order to explore the influence of the temperature of cyclone mixer and urea injection flow rate on NO_(x) conversion efficiency,CFD technology is used to study the SCR catalytic converter for a diesel engine by chemical reaction and steady flow numerical simulation.By changing the temperature of the cyclone mixer and the urea injection flow rate,the concentration and uniformity coefficient of NH and the mass fraction of NO_(x) at the outlet are compared under different conditions.The results show that the mass fraction distribution of NO_(x) at the outlet of SCR catalyst presents the law of low center and high edge,and the temperature change of cyclone mixer has little effect on the uniformity coefficient of NHvelocity.When the temperature is 400℃,the NH distribution is more uniform,the NH generation rate and NO_(x) conversion efficiency are higher.These results indicate that the NO_(x) conversion efficiency and urea utilization rate can be improved by selecting the appropriate urea injection flow rate.

关 键 词：柴油机 SCR CFD 选择性催化还原 数值模拟 均匀性系数 NO_(x)转化效率 尿素利用率 

分 类 号：TP31[自动化与计算机技术—计算机软件与理论] TN99[自动化与计算机技术—计算机科学与技术]